Production of hydrocarbon fuels



April 16, 1940. A. E. PEw, JR

PRODUCTION 0F HYDROCARBN FUELS 2 Sheets-Sheet 1 Charg Filed Dec. 19,1956 Chad e aci/baai? bbl Y. T J R Y me M E V T mm/.M .b u, .nM Am` FvApril 16,1940. 5 A.E.PEw,JR 'l 2,191,008

PRODUCTION 0F- HYDROCARBON FUELS Filed Dec. 19, 1936 2 Sheets-Sheet 2INVENTOR E'ThurEFew JY'.

ATTORNEY Patented Apr. 16, 1940,

UNITED STATES PATENT .OFFICE Arthur E. Pew, Jr., 'Bryn Mawr, Pa.,assignor, by

mesne assignments, to Houdry Process Corporation, Wilmington, Del., acorporation of Dela- Application December 19, 193s, serial No. 116,6991o claims. (ci. 13s-49) The present invention relates to the lart oftreating iiuids, especially hydrocarbon fluids.

i More particularly the .invention involves the treatment of compositehydrocarbon fluids having a Wide or substantial boiling range andderived from petroleum, coal, shale or other origin,.

natural orvartificial.

My invention is concerned with transforming or converting such rawhydrocarbons or charge,

for example, crude petroleum oil or topped crude,v

into lower boiling hydrocarbons, in the carrying out of which catalyticand pyrolytic operations, and apparatus therefor, are employed ininterdependent relationship and in such combination that advantages andeconomies, both in process and apparatus, are thereby secured.

The charge to the system, e. g., crudepetroleum oil, topped crude or thelike, is divided in to a plurality of fractions: (1) a high boiling orre sidual fraction, (2) a lower boiling fraction comprising componentsvwithin the gas oil boiling range and/or the naphtha boiling, ran'ge, and(3) catalytically, if desired. 'Ihese fractions (exclusive of theoverheadv gasoline fraction, which may be treated as desired) aretreated catalytically and pyrolytically, the' heavy or residual fractionbeing treated catalytically and the aforesaid lower boiling fractionbeing treated pyrolytically, and the synthetic crudes or products ofeach of such conversion operations are passed int`o a common separatingzone or fractionating column, preferably without any recycling, up tothis point, between the catalytic and pyrolytic operations. A relativelylow amount of steam, or

the like, is required with the hydrocarbons treated in the catalyticzone.y A residual or heavy fraction or fractions and possibly oneor moreside stream fractions may be withdrawn from the products separator orsynthetic crude column and subjected to a further pyrolytic conversion,or, according to a permissible mode of operation one or both of theserecycle fractions may be catalytically treated or converted." Butblending of the catalytic and pyrolytic synthetic crudes is effectedpreliminary .to the further'conversion or cracking of partlyconvertedmaterials. The products of this latter conversion operation oroperations may, if desired, be introduced into the aforesaid productsseparator or fractionating column and separated into fractions alongwith :the `aforementioned catalytic and pyrolytic synthetic crudes. Thezone'or zons for handling re- Y cycle from the products fractionator orseparator may be separate from or the same as those which receive andconvert .fractions coming from the "crude tower.

However where, for example, a fraction from the products fractionator,which it is desired further to convert pyrolytically, is of -a higher orsubstantially different boiling range than the fraction -fromthe crudetower which is being pyrolytically convertedthen it is ordinarilypreferable separately to convert such recycle fraction. This would bethe case, for example, where the lower boiling fraction from the crudefractionator consisted of 'a naphtha,-1e. g., a, 1

heavy naphtha, to be pyrolytically treated or re formedwhereas thefraction from the'products fractionator which it was desired further toconvert was in the gas oil boiling range, e. g., intermediate boilingrange gas oil.

According'to a preferred aspect of this nven vtion the catalytic zonesor converters handle onlyvirgin stock or a previously untreated fractionof the charging material while the pyrolytic zone handles virgindistillate, once catalytically q cracked material and recycle stockfrom-prod ucts ofvpyrolytic conversion. 'I'he insufciently catalyticconversion are, however, as above indie cated, *preferablyv not sentdirectly to apyrolytic zone or zones. Rather the synthetic crudes ofboth catalytic and pyrolytic conversionare blended together, forexample. inthe products fractionator, and then la fractionor fractionsis or are separated out and sent to a pyrolytic cori-- vversion zone.

The type and proportions offractions sepaflrated by. the crude. tower or-`fractionator f or charge and sent respectively to catalytic andpyrolytic zones are regulated so as to control the desired final productor gasoline withdrawn from the products separator or fractionator.,Without changing theconditipns of operation of thecata-4 ,lytic andpyrolytic-units to substantial extent,

'converted fraction "or fractions of the-products of by controlling thecharacter and 'relative amount of charge to each, a hydrocarbon productor gaso-` line having controlled characteristics and comprising arelatively stable blendxof pyrolytically cracked gasoline,catalyticallylcracked gasoline,

reformed naphtha and/or straight .run gasoline. is produced. By suchcontrol the boiling. range least with most charging materials, thesulfur content can be held within predetermined limits,

except for the possible necessity of removing some hydrogen sulfidepresent in the products issuing from the products fractionator. 'Ihefraction or fractions sent to the catalytic zone or zones contains `asubstantial portion and often most of the sulfur content of the'original charging material and the catalyst employed, in additionto'performing its principal function of transforming higher boilinghydrocarbons into lower boiling hydrocarbons, converts combined sulfur,for example mercaptans, into hydrogen sulfide andlor retains the sulfuras a sulfurous deposit on the catalyst. The catalyst usedoomprisessilicious material, for example an activated hydrosilicate of alumina ora blend of silica and alumina, preferably in molded form of cylindricalor annular shape for example, as illustrated in Patent' No. 1,837,971,issued to Alfred Joseph on December l22, 1931, or in modied compositionsas illustrated in the copending applications of Eugene J. H oudry,Serial No. 600,581, led March 23,1932, which issued on May 4, 1937 asPatent No. 2,078,945 or Serial No. 35,101, nled August 7, 1935, whichissued on May 4, 1937 as Patent No. 2,078,951. l

In addition to the advantages set out hereinabove, it is a furtherobject of this invention to provide for a high percentage conversion ofhigher boiling hydrocarbons into lower boiling hydrocarbons, such asvgasoline. The steps of process are arranged and elements of apparatusarecombined so as efdciently to produce a high quality product ofcfontrolled characteristics while d effecting heat economies andeconomies of equipment. In a preferred aspect of this invention it isarranged to simultaneously employ 'both cata'- lytic and pyrolyticoperations in producing a deaired motor` fuel or gasoline while sendingonly virgin stock as charge to the catalytic conversion zone. It is alsoan object of this invention to minimize or avoid treating the iinalproduct o r motor fuel for the elimination of organic sulfur (i. e.,sulfur united in a molecule with carbon and hydrogen) l while producinga product ofother desired characteristics-from which, however, hydrogensulde may or may not be removed. It is an object oi.' this invention4toproduce a motor fuel of suitably high octane rating at a low costwhile preferably avoiding the recycling of a heavy' fraction orfractions of the catalytic synthetic crude back to a catalyticconversion zone, Other and more speciilc objects and advantages willappear from thedescriptlon which follows.

Important characterizing aspects of this inventionare: (1) relativelylow consumption of steam in eiiecting catalytic conversion; (2)' passageof products oi'4 catalytic. conversion, or at least a' large partthereof, directly to the products frac- For a ready understanding ofillustrative aspects of this invention, reference is had to theapparatus indicated in the accompanying drawings in which:

Fig. 1 shows diagrammatically the assemblage of apparatus, includingcatalytic and pyrolytic converters, a tower for preparing charge and afractionator or separator for receiving products, as well as otherelements of apparatus, connected in a particular and interdependentrelation, lto .provide a complete commercial apparatus for making motorfuel, gasoline or the like from higher boiling hydrocarbons;

Figs. 2, 3 and 4 are modications of the apparatus shown in Fig.` 1.

Referring more in detail to the drawings, in the several figures ofwhich like reference characters drocarbons or charging material; 2a, 2b,2c and 2d, appearing in the same respective figures, are products towersvor -rectifying columns for receiving products of conversion andseparating out desired product or motor fuel therefrom. 3a and "and apressure of atmospheric to 75 lbs./sq. in.,

preferably near atmospheric'. A feed -rate of 8/20 (8 liters of oil perhour per 20 liters of catalyst) to /20, e.`g.,v16/20, is suitable,although higher or lower rates may successfully be used.

An illustrative operation will first be described by specific reference.to Fig. 1 of the drawings.

The'starting material or charge will, by way of example,- be consideredto'be a whole crude petroleum oil. The incoming charge passes throughheat exchanger 5a and then through heater 8a into fractionating columnla, where the charge is divided into several fractions. An overheadfraction comprising gasoline and hydrocarbon gases' is withdrawn fromthe top of crude tower la, as shown. A residual 'fraction is withdrawnfrom the bottom of tower la` and is forcedby pump 1a through heater orviscosity breaker 8ain catalytic zone-BI. During passage` through 8asteam or the like in small amounts may be introducedwith the residualhydrocarbon fraction to control the viscosity breaking operation asdesired. Products from viscosity breaker la pass towtar separator .9awhere heavy, unvaporized components are removed and withdrawn throughline Ita. Overhead from the tar separator passes to one or the otherconverters 3a or la.

Under ordinary lconditions of operation at a given time only one of theconverters 3a or la is of catalytic on stream effecting the desiredcatalytic conversuch as air, being fed to said converter lundersion orreaction, while the other converter is undergoing regeneration, aregenerating medium, 65

going regeneration through one of the lines 2O free of components whichcannot readily be vapori'zed without thermal cracking, is withdrawn as'aside stream from column la through theline shown and is. forced by pumpIla through heater IIa, in which a minor amount, if any, viscosity or 21while the products of regeneration-are removed through the other of saidlines. y .A A second fraction, which is to be catalytically.

converted in zone BI and which is substantially aieacos breaking may becarried out. This fraction may have an end boilingpoint of the order of725 to 800 F., e. g., 750 F. Steam in small amounts may be introducedinto this side stream fraction while the same is passing through theheater I2a through the valved line shown, if desired, although this isordinarily not necessary. The heated fraction leaving the heater l2a maybe passed directly to one or the other of catalytic converters 3a or 4aor, permissibly, may be passed through valved line |3a into and throughthe tar separator, though this latter operation is seldom employedexcept to control the removal of tar or unvaporizable components fromthe residual fraction. In' any event this fraction is combined with thetar separator overhead of the residual fraction and minimizes the amountof steam required to keep the latter in a suitably vaporous condition.

Products of reaction from catalytic converters 3a or 4a pass, withoutcondensation, directly to the rectifying column or products fractionator2a.

A lighter side stream fraction, consisting for example of a heavy orlight naphtha having a boiling range up to about 550 F. for example,with an initial boiling range of about 250 F. or higher, is withdrawnfrom tower la through the line shown and passed .to pyrolytic zone AIcomprising heat exchanger Ila and pyrolytic converter |5a. The pyrolyticconverter or still may be maintained at a temperature of '150 to 1200 F.and a pressure of atmospheric or slightly below to 2500 lbs/sq'. in. orhigher. The products from the pyrolytic converter pass into vaporseparator I6a where heavy carbonaceous or unvaporizable components areseparated from the remaining vapors, the latter passing in heat exchangewith the incoming charge to the pyrolytic zone through heat exchanger Maand thence into productscolumn 2a along with the catalytic syntheticcrude from converter 3a or la. The reaction which takes place in thepyrolytic still is one of cracking or converting materials heavier thangasoline into products of the gasoline boiling range and/or of thermallyreforming naphtha to improve its antiknock characteristics.

The blended pyrolytic and catalytic synthetic crudes are fractionated intower 2a, from which an overhead-fraction consisting of the desiredproduct or gasoline is withdrawn and from which a residual fraction iswithdrawn and forced by pump l'la through a secondpyrolytic zoneAI lcomprising pyrolytic converter or cracking still I8a and a' vaporseparator lila where high boiling or carbonaceous liquidsvarewithdrawn-from the remaining vapors and the latter are passed in heatexchange with incoming charge in exchanger 5a and thence into thefractionating column 2a.`

The apparatus illustrated in Figs. 2,'3 and 4 as well as the generaloperation of each, will be generally understood from the descriptiongiven in connection with the apparatus illustrated in Fig. 1 and thesimilar indication of like parts in the different figures. For example,capital letters followed by the numerals 2, 3 and 4 indicate thepyrolytic and catalytic zones while numerals followed by the letters b,c or d in Figs. 2, 3 or 4, respectively, are similar to the partsdesignated and forced by the pump shown through heat exchanger 2| andthence, together with any desired volume of side stream fraction shownfrom products column 2b, into and through pyrolytic converter or stillI5b, may have a higher boiling range than the upper side stream fractionof Fig. 1. For-example, the side stream fraction of Fig. 2 may have anend boiling point of the order of 575 to 650 F., e. g. about 600 F. The

-, outgoing products of the pyrolytic conversion zone A2 pass in heattransfer relation with the incoming feed to the system in exchanger 20,or with any portion thereof, as desired, and then flow through the lineshown into an intermediate point in products column 2b, below the pointat which a side stream fraction may be withdrawn therefrom. The sidestream fraction withdrawn from column Ib in Fig. 2 is of an averageboiling point intermediate that of the two side stream fractionswithdrawn from. column la in Fig. 1 and may be considered as containingcomponents in the light gas oil as well as the naphtha boiling range.Also, the problem of heat economy or heat transfer is handled quitedifferently in the apparatus oft Fig. 2 from that shown in the apparatusof Fig. l. In Fig.. 1 the catalytic synthetic crude passes directly intothe products fractionator while in Fig. 2it first passes in heatexchange relation with the side stream fraction from the crude tower soas to help to bring that fraction to a temperature suitable forpyrolytic conversion. in Fig. 2 passes in heat exchange relation bothwith the catalytic synthetic crude and the pyrolytic synthetic crude inheat exchangers 22 and y20, respectively.

'Ihe apparatus shown in Fig. il differs from that shown in other figuresof the drawings in that a residual fraction from the products column 2cis passed, along with the lower side stream fraction from crude tower lcthrough heater l2c of catalytic zone B3 and finally through catalyticconverter 3c or 4c. The apparatus of Fig. 3 also provides forwithdrawing a light side stream fraction from the products tower 2c andpassing it, as well as a side stream fraction from the crude tower oflike or similar. boiling range to pyrolytic zone A3 and throughconverter or still I5c. The outgoing vapors from the pyrolyticconvertershown may pass in heat exchange with the incoming feed orcharge to the system in Heat exchanger 20c. Then the pyrolyticallyconverted products pass through the line shown and incoming charge orwith any desired portion' thereof in heat exchanger 22c. 'While theapparatus of this figure has the advantages pointed out, it does havethe disadvantage that the higher boiling or residual 'fraction from theproducts' Also the fresh charge to the system column 2c is passedthrough the catalytic converter shown. Thatv is, in this case thecatalytic conversion zone is forced to han'dle, to some small extent,material other thanl virgin stock.

Fig. 4, in distinction to the other figures of the drawings, illus ratesa type of operation ,Where the catalytic-synthetic crude is cooledbyfheat` exchange with .incoming charge in exchanger 22d so that a part,i. e., thehighest boiling part of o thel catalytic synthetic crude fromzone B4 is condensed from the remaining vapors. Thisv high boiling partor condensate is then forced by pump 3|` through line 24 to be usedselectively as makeup material for the' 'charge to zone A4 or some orall of it maybe sent by line 26 into cooling, re-

' action arresting or quenching zone indicated at 30 to serve as acooling or Vquenching medium for vapor phase, thermally crackedsynthetic crude lin pyrolytic zonel A4, thereby to arrest furtherthermal conversion and hence to -avoid undesirable secondary reactionsin1the pyrolytic syn-f thetic crude.

The apparatus of Fig. 4 is dissimilar to that shown in Figs. 1 and 3especially in that only one side stream Vfraction is withdrawn fromcrude tower Id, somewhat similar to Fig. 2, although.

`the side stream fraction in Fig. 4 may be generally of lower boilingrange than in Fig. 2. However the boiling range of the side streamfraction maybe controlled by selecting distillate through either of thebranch lines shown, as desired, as

.wellas by controlling the operation of the tower.

Further, the. catalytic synthetic crude is passed only in heat exchangewith incoming charge before entering the products tower 2d and does notpass both in 'heat exchange relation with the side stream. fraction fromthe crude tower aswell-as with the incoming charge, in the initial stageof drawn 'from products tower 2d and any desired portion thereof passedthrough cooler or heat 'exchanger 28 and thence forced by pump 29 backinto the column 2d, li'or example. at a point above that at which thepyrolytic synthetic crude is' introduced into the products fractionatorand at a point-below that at which the partially converted side streamfraction may be withdrawn from the products fractionator.

Y It win be; noted tnatr'igsl 3 and 4 include a showing of a condenser Cand gas and water separatorv D in circuit following the productsfra'c#tionator for recovering the desired product from the overhead of theproducts fractionator; V i This 'invention discloses an operation inwhich there is a very high conversion of crude charge into gasoline orlight motor fuel, while keeping l down steam consumption for catalyticconversion to a low point.v For example, the steam consumed may be keptwell under 10% by weight of the -charge to the catalytic converters, andmay be downto 5% thereof, orlower, -depending uponv the average boilingpoint' or average molecular weight of .material going into the tarseparator.

carbons from hydrocarbon charge composed to substantial extent of higherboiling hydrocar-- bons." the steps which comprise dividing the chargeinto at least two fractions of different Y boiling ranges, a lowerboiling fraction and 'a higher boiling fraction. said lower boiling.fraction being composed substantially of components at least as highlboiling as gasoline. passing "said Y higher boiling fractionthrough acatalytic reaction zone maintained under conditions capable of effectinga transformation thereof into lower boiling hydrocarbons of highanti-knock rating and sona catalytic mteriaicapable of promoting thesaid transformationfpassing said lower boiling fraction through apyrolytic conversion'zone while auch fraction under Pyrolytic conversionconditions so 'fs to effect a substantiat conversion thereof into 'chem-9,107,008 y licall'y different hydrocarbon compounds of yimprovedanti-knock characteristicsJalending products of the catalytic -andpyrplytic conversions without substantial intervening condensationthereof, fractionating the blended products in a products fractionatingzone, withdrawing a high boiling fraction from said productsfractionating zone, said high boiling vfraction .being composedprimarily of components substantially above the gasoline boiling range,subjecting said fraction to a.- further cracking or conversion,introducing fluid products of such-conversion back int the said productsfractionating zone, and withdrawingI as desired product a light fractionwhich comes within the motor'fuel range from said vfractionating zone. n

2. In the production of lower boiling hydrocarbons from a wide boilingrange charge composed largely lof higher boiling hydrocarbons, theprocess steps comprising dividing said charge intov at least twofractions of different boiling ranges, 'a lower boiling fraction and ahigher boiling fraction, said lower boiling fraction being composed tosubstantial'extent of compo' nentsat least as high boiling as gasoline,passing said higher boiling fraction through a catalytic reaction zonecontaining an adsorptive con' tact Vmass capable of eiiectingtransformation thereof to substantial extent into lower boiling ohydrocarbons of lthe gasoline type, said catalytic reaction zonebeing'maintained under conditions which favor said transformation,passing said l lower boiling'fraction through a pyrolytic conversionzone while maintaining said fraction under conditions suitable forpyrolytic conversion `to produce high anti-knock motor fuel of thegasoline type, f ractionating products of said pyrolytic conversiontogether with products of said catalytic transformation in a commonprode? ucts fractionating zone, withdrawing from the latter 'a motorfuelproduct comprising a blend of pyrolytically and catalyticallyconverted products, withdrawing also from said fractionat- .ing zone astream of partially converted hydrocarbons higher'boillng than saidblended motor fuel product, subjecting said stream to pyrolyticconversion conditions to produce therefrom further amounts of pyrolyticproducts having the products of said last named pyrolyticconversionboiling range of said motor fuel, and returning' I A to saidll'ractionating zone to -be fractionatedftherein along with the otherconversion products.

3. In the production ofvlower boiling hydrooarbons, within,the gasolineboiling range from a higher boiling hydrocarbon charge having a wideboiling range, the -steps which comprise dividing the charge into atleast two fractions ofl different boiling ranges, alower'boilingfraction and a higher boiling fraction, said lower boilingfraction being composed at least to substantial extent of componentsabove the gasoline boiling range. passing said higher,4 boiling,fraction through a catalyst reaction zone maintained un; der conditionscapable of effecting a cracking of such fraction intp lower` boilinghydrocarbonsfsaid reaction zone containing solid catalytic materialcapable of promoting the saidcracking,

passing saidilower boiling fraction through al pyrolytic conversion zonewhile maintaining such fraction under'temperature and pressureconditions of pyrolytic conversion so as-to eifect a substantialtransformation or conversion thereof into hlghoctane hydrocarbons withinthe gasoline boiling range, fractionating fluid products of both thecatalytic' and pyrolytic conversions in condensate fr'om remaining lowerboiling vapora produc-ts fractionating zone, withdrawing therefrom aside stream fraction having boiling range characteristics substantiallysimilar to those of the aforesaid lower boiling fraction of the originalcharge, sending said side stream fraction from the products fractionatoralong with said lower boiling fraction of the original charge to theaforementioned pyrolytic conversion zone, and withdrawing as desiredyfinal product from said fractionating zone a light fraction composed atleast largely of components within the gasoline boiling range, saidlight fraction comprising a blend of catalytically and pyrolyticallycracked hydrocarbons of good chemical stability and high anti-knockrating.

4. In the production of a light motorfuel comprising gasoline from crudepetroleum oil having a wide boiling range and composed predominantly ofhydrocarbons boiling above the range of the Y,

desired light motor fuel product, the steps which comprise dividing suchcharge into straight-run gasoline, a residual fraction and a side streamfraction which is lower boiling than said residual fraction but higherboiling than gasoline, passing said sidestream fraction through apyrolytic conversion zone while maintaining the same under pyrolytioconversion conditions so as to effect a cracking thereof to substantialextent into hydrocarbons within the gasoline boiling range, passing thesaid residual hydrocarbon fraction through a catalytic cracking zonecontaining a catalyst comprising an active, adsorptive blend of silicaand alumina and maintained under conditions capable of effectingconversion of'a substantial proportion of said residual fraction intohydrocarbons within the gasoline boiling range, owing fluid hydrocarbonproducts from the catalytic -and pyrolytic cracking zones, substantiallyin vapor phase, into a products fractionating zone, fractionating theresulting products within said products fractionating zone, withdrawinga high boiling fraction from' said products fractionating zone,subjecting' at least the major proportions of the last-mentionedfraction to pyrolytic conversion, cooling products.

of thelast-mentioned conversion by heat interchange with theaforementioned whole crude petroleum oil charge and then passingproducts so cooled into the aforementioned products fractionating zone,withdrawing a fraction composedpredominantly of components within thegasoline boilingv range from said products fractionating zone, andblending the last-mentioned fraction with the aforesaid straight-rungasoline from the original crude petroleum charge so as to form thedesired light motor fuel product.

5. In the production of lower boiling hydrocarbons from higher boilinghydrocarbon charge of wide boiling range, the steps which comprisedividing the charge into at least two fractions of different boilingranges, a lower boiling fraction and a higher boiling fraction, saidlower boiling fraction being composed, at least in substantial part, ofhydrocarbon components above the gasoline boiling range, passing saidhigher boiling fraction through a catalytic reaction zone maintainedunder conditions capable of effecting. a transformation thereof intolower boiling hydrocarbons 'of high anti-knock rating, said catalyticreaction zone containing solid adsorptive silicious catalytic materialcapable of promoting the said transformation,v withdrawing fluidproducts of reaction from said catalytic reaction zone and condensingand separating a portion of the higher boiling components of suchproducts as ous components, passing the aforesaid lower boiling fractionof the original charge through a pyrolytic 'conversion zone whilemaintaining such from said cooling zone and the aforementioned ivaporous components of'the products from said catalytic conversion zoneinto a products fractionating zone, and withdrawing from said productsfractionating zone a lower boiling hydrocarbon fraction composedpredominantly of components within the gasoline boiling range, therebyeconomically to produce a desired light motor fuel comprising a blend ofcatalytically and pyrolytically cracked hydrocarbons.

6. In the production of lower boiling hydrocarbons, including componentswithin the gasoline boiling range, from a higher boiling hydrocarboncharge, the steps which comprise dividing the charge into at least twofractions of different boiling ranges, a lower boiling fraction and ahigher boiling fraction, said lower boiling fraction being composed atleast to substantial exi tent of components higher boiling thangasoline. passing said higher boiling fraction through a conned zonecontaining an active silicious catalyst under conditions capable ofeffecting a cracking thereof into lower boiling hydrocarbons, passingsaid lower boiling fraction through a pyrolytic conversion zone whilemaintaining such vfraction under'desired pyrolytic conversion conditionsso as to eifect a cracking or transformation of a substantial proportionthereof into low boiling hydrocarbons in the light motor fuel orgasoline boiling range, passing vaporous products of the catalytic andpyrolytic conversions, without substantial preliminary condensationthereof, into a products fractionating zone,'fractionating the resultingblended products in said products fractionating zone, withdrawing asdesired product a light fraction which comes within the motor fuel rangefrom 4said fractionating zone, withdrawing as` a side stream from saidproducts fractionating zone a fraction composed primarily of componentswithin the gas oil boiling range and capable of being readily convertedinto gasoline, and withdrawing a fraction from said fractionating zone,adjacent the bottom thereof, cooling a portion of said last-namedfraction and returning the same to said products fractionator at Ialevel above that from which it was withdrawn so as "to maintain thetemperature of the bottom of the products tower within the preferredrange in order to control the boiling range characteristics of saidlight fractionor desired r'notor 'fuelnroduct within desired limits.

7,. Apparatus for producing a motor fuel composed of a blend ofcatalytically and pyrolytically converted products from a crudehydrocarbon charge comprising a fractionator for crude charge, aconverter havinga reaction chamber, a\ solid adsorptive catalyst in saidreaction chamber, fluid conducting means joined between a point towardthe bottom of said iractionator and said converter for conducting chargefrom the former to-the latter. a products tower for fractionatingproducts of conversion, a :duid conduit leading from said converter to apoint intermediate the ends of said tower to'transfer products ofreaction from the former to the latter, a pyrolytic reaction chamber orconverter, a' duct for passing a lower boiling fraction from saidfractionator for charge to said pyrolytic reaction chamber, a conduitfor passing products of reaction from said pyrolytic reaction chamber tosaid products tower, a second pyrolytic converter,l

means including a duct for passing a fraction substantially higherboiling than gasoline from said products fractionator to said secondpyrolytic converter, a duct for returning products of reaction from saidsecond pyrolytic converter to a point in said products towerintermediate the ends thereof, means for effecting transfer of heat fromproducts of conversion to charge or portionsl thereof before the sameundergoes conversion,

-and a lead oil adjacent the top of said products -tower for withdrawingdesiredlow boiling motor fuel product. y

` 8., Apparatus for producing a low boiling motor fuel composed of ablend of catalytically and pyrolytically converted products from a crudehydrocarbon charge comprising a fractionator for crude charge, acatalytic conversion system co'm-v pricing,r a heater for heating chargeto the system at reaction temperature and acatalytic converterlfollowing and connected to said heater, said converter having areaction chamber, a solid adsorptive silicious catalytic material insaid reaction chamber, `iuid conducting means joined .between a pointtoward the bottom of said fractionator and said heater for conductingcharge from the former to the latter, a products tower for fractionatingproducts of conversion, `a fluid` .conduit leading from said converterto a point intermediate the ends of said tower to transfer products ofreaction from the former to the latter, a pyrolytic reaction chamber orconverter, a duct for passing a lower boiling fraction fromsaidfractionator for charge to said pyrolytic reaction chaniber, aconduit for passing products of reaction from said pyrolytic reaction'chamber f to said products tower, means including a duct pyrolyticallyconverted products from-a crude hydrocarbonfcharge comprising afractionator for crude charge, a converter containing an activecatalyst, uid conducting means joined between 'a pint toward -the bottomof said fractionator and said converter for conducting charge from theformer to the latter, a partial condensing means, a iuid lead from saidconverter to said partial condensing means, a products tower forfractionating products of conversion, a fluid conlduit leading from saidpartial condenser to .a

point intermediate the ends of said tower for passing products in vaporform, freed of condensed higher boilingcomponents, from the former tothe latter, a pyrolytic reaction chamber or converter, a duct forpassing a lower boiling fraction from said fractionator for charge tosaid pyrolytic reaction chamber, a quenching chamber,- a uid lead forpassing iluid productsvfrom theA .said pyrolytic reaction chamber tosaid quenching'chamber, means including a conduit for passing condensedportions of the products of catalytic conversion from the aforesaidpartial condensing means into said quenching chamber, a ductffor passingfluid from the latter chamber to a point in said products towerintermediate the endsl thereof, means including a duct for pass, ing afraction substantially higher boiling than gasoline from said productslfractionator so that the same may be further converted,- and a lead oiffor crude charge, a duct for withdrawing. ,straight-run gasoline fromsaid fractionator, a

converter adapted to contain a catalyst; iluid conducting means joinedbetween a point toward the bottom of said fractionator and saidconverter for conducting charge from the former to the latter, aproducts tower for fractionating products of conversion, a fluid conduitleading, from said converterpto a point intermediate the ends of saidytower to transfer products of reaction l from the former to the latter,a pyrolytic reaction chamber or converter, a duct for passing a lowerboiling fraction from said fractionator for charge to saidpyrolyticreaction chamber, a conduit forv passing products of4 reactionfrom -said pyrolytic reaction 'chamber to said products tower, meansincluding a duct for passing a' side stream fraction which is higherboiling than gasoline from said products fractionator, a conduit forwithdrawing a fraction from a point adjacent the bottom of said productsfractionator, means for cool-- ing at least a portion of thelast-mentioned fr action, means for returning at least a portion of saidlast-mentioned fraction to said products tower toward the lower endthereof, thereby to' provide for controlling the Atemperature of thelower end of said tower,and means adapted 'to withdraw a gasolinefraction from adjacent the top of said products tower tobring itintoadmixture with the iiuid'passing from the aforesaid fractionator forcrude `charge through the said duct for withdrawing straight-rungasoline,v

therebyto provide apparatus for the production. of a desired blend ofstraight-'run and catalytically and pyrolytically cracked gasolinas.

. ARTHUR E. 132W. Jn.'

v CERTIFICATE OF CORRECTION. patent No, 2,197,008. f -Aprii 16, 19km.

E. PEW, JR. It is. hereby certified that error appears in the printedspecification of the above numbered patent requiring correction 'asfollows; Page 5, first column, line l, claim 5,-before the 'vvord"products" insert -A- comonn; and that the said Letters Patent shonld beread with this correction 'therein that theI same my clomfolf'm to therecord of the case-in the vPatent Office.

signed and sealed thstth-dayof June, A. D. 19m).

Henry Van Arsdalem,

(Seal) l Acting Commissioner of Patents.

